The present invention relates generally to a headlamp system, and more particularly to a headlamp system having a plurality of digitally stored beam patterns.
There are several beam patterns necessary for a vehicle""s headlamps, such as high beams, low beams, turning beams, fog beams, daytime running beams, and others. In addition, there are different standards for beams outside of the U.S. For example, European beam requirements are different from Japanese beam requirements, and both are different from U.S. requirements. Currently, different lamps must be used or complicated beam adjustments must be made to the headlamp system for adjusting the beam patterns as desired.
Current technology for headlamp beam adjustment employs mechanical adjustments to the beam patterns. For example, multiple lamps, lenses, and motors are used to steer the lamps and lenses in order to provide the desired beam pattern. For example, a motor is used to steer a lamp to illuminate a corner when making a turn. The mechanical steering system typically includes auto-leveling systems, left-right actuation motors, a long wave infra red (LWIR) camera and other mechanical light aiming devices. These systems are not only complex and costly, but they also require significant packaging space thereby complicating packaging constraints.
Thus there is a need for a simplified system and method for providing a plurality of headlamp beam patterns. In addition, there is a need for providing a predetermined or desired headlamp beam pattern from a plurality of stored patterns upon demand.
It is an object of the present invention to deliver a predetermined beam pattern to a headlamp. It is another object of the present invention to digitally store a plurality of headlamp beam patterns that are activated and delivered to a headlamp upon demand.
It is a further object of the present invention to utilize a digital micro-mirror device to store and change beam shapes to a desired headlamp beam pattern. It is still a further object of the present invention to use appropriate vehicle parameters to determine the proper headlamp beam pattern to be delivered to and displayed by the headlamp system.
In carrying out the above objects and other objects and features of the present invention a method and system for providing a predetermined headlamp beam pattern using light distribution optics from a digitally stored beam pattern in a digital light processor is provided. The present invention is applicable to conventional headlamp systems for providing an improved method of creating and displaying high beam, low beam, fog lamp, daytime running lamp patterns, as well as side beams for turning without the need for added lamps and complicated motors.
The present invention is especially applicable to a high intensity discharge (HID) lighting system which uses a centralized HID light source that is integrated with drive electronics. A light source is coupled to a bundle of fibers that deliver light to a headlamp, or a terminated fiber optic bundle, to form a headlamp beam pattern. According to the present invention, the output of the headlamp is controlled by a digital beam pattern that is stored on a microprocessor and processed upon demand by a digital micromirror device (DMD). The DMD is capable of generating a plurality of beam patterns that can be created by adjusting the position of individual pixels on the DMD.
Several vehicle parameters can be used as inputs to the microcontroller in order to determine the appropriate beam pattern to be produced by the DMD and projected by the headlamp system. In addition, the beam pattern created according to the present invention is better defined and more precise due to the fact that each pixel in a pixel array on the DMD is addressable by the microcontroller.
Another advantage of the present invention is the flexibility provided in storing predetermined beam patterns and commanding the headlamp system to display the desired pattern upon demand. In addition, the headlamp system is simplified over systems known in the art, because there is no need for auto-leveling systems, left-right actuation motors, LWIR cameras and other mechanical light aiming devices employed used in the prior art. Also, any electromagnetic interference that was of concern with the motors used in the prior art is eliminated.
Other objects and advantages of the present invention will become apparent upon reading the following detailed description and appended claims, and upon reference to the accompanying drawings.